A mobile communication system has been developed in order to provide voice services while ensuring user activity. However, development of mobile communication systems has gradually been extended to data services as well as voice services and has currently been developed to the extent that can provide a high-speed data service. However, in a currently provided mobile communication system, due to resource lack and user requirements for a higher-speed service, more advanced mobile communication systems are required.
As one of the most important requirements of next-generation radio access systems, high data transfer rate requirements should be supported. For supporting high data transfer rate requirements, various technologies such as multiple input multiple output (MIMO), cooperative multiple point transmission (CoMP), carrier aggregation (CA)/multiple cells or relays have been researched.
In order to obtain maximum performance using such technologies, it is difficult to equally use a downlink control channel used in a legacy system. Thus, in a 3GPP LTE-A system, an enhanced physical downlink control channel (E-PDCCH) has been introduced in order to increase capacity of a physical downlink control channel (PDCCH) of a legacy 3GPP LTE system.